Apparatus for detecting failure of the nuclear fuel rod

Abstract

An apparatus for detecting failure of the nuclear fuel rod has an outer cap and 16 (sixteen) inner caps. In checking for any faulty fuel rods, the outer cap is placed to cover the upper ends of 16 (sixteen) fuel assemblies mounted in the reactor core, while the inner caps in the outer cap are disposed on corresponding one of the fuel assemblies. To the outer cap are attached 4 (four) air supplying hoses. The inner caps receive corresponding one of 16 sampling tubes attached to the outer cap, and coolant sampling hoses are connected to the sampling tubes. A bundle member is fixed to the center of the upper surface of the outer cap. The four air supplying hoses and 16 coolant sampling hoses are fixed to the bundle member. The bundle member has a handle attached thereto.

We claim: 
     
       1. An apparatus for detecting a failure of a fuel rod comprising: an outer cap adapted to cover the upper end portions of fuel assemblies mounted in a core of a nuclear reactor and containing therein coolant; a plurality of inner caps disposed in said outer cap, and arranged to cover said upper end portions of said associated fuel assemblies, respectively; means, disposed in said outer cap, for guiding said inner caps so as to enable said inner caps to move up and down with respect to said outer cap independently from one another; a plurality of coolant sampling tubes respectively attached to said inner caps and having opened ends inserted into said associated fuel assemblies; sucking means, attached to said coolant sampling tubes, for sucking coolant from said fuel assemblies; a gas supplying pipe connected to said outer cap and opening to a space defined by the surface of said outer cap confronting said fuel assemblies, and means for supplying a gas to said gas supplying pipe. 
     
     
       2. An apparatus as claimed in claim 1, wherein said cap is sized to just cover the upper ends of 16 fuel assemblies mounted in said reactor core, and is provided with 16 coolant sampling tubes. 
     
     
       3. An apparatus as claimed in claim 1, wherein said outer cap is sized to just cover the upper ends of 16 fuel assemblies mounted in said reactor core, and wherein 16 inner caps and 16 coolant sampling tubes are provided. 
     
     
       4. An apparatus as claimed in claim 1 or 2, wherein a bundle member is attached to the surface of said outer cap, and said coolant sampling tubes and said gas supplying pipe are bundled through said bundle member. 
     
     
       5. An apparatus as claimed in claim 1, wherein each of said inner caps is provided with a plate-like guide member adapted to guide said each inner cap along with a handle attached to each fuel assembly. 
     
     
       6. An apparatus as claimed in claim 1, wherein each of said inner caps has a lower portion engaging said upper end portion of a respective fuel assembly so as to isolate said fuel assemblies from one another.